The only 15mg Codeine Sulfate products I know about from India are in fact tylenol free. Although I suppose there is a small possibility that they slipped you some T2's, it seems unlikely. The Indian Codeine-only product is widely available, and there is no reason for them to sell you tylenol 2 or 3 instead.
Did they come loose, or in blister packs or foil packs? What did the blisterpacks say on the back? OR was there no product literature at all?
I have had loose codeine pills shipped from various Indian and Pakistani IOP's, and they always included either a product insert or they left a couple of tabs in the original foil or blisterpack, with the contents clearly indicated.